The project concerns assembling chemical and ultrastructural data in order to establish the way natural products function in plants as well as their role in coevolutionary systems involving plants and animals. The investigation emphasizes the phenolics, terpenoids and alkaloids present in members of the Compositae genera Helianthus and Artemesia, as well as other genera including especially Passiflora and Salvia. The antiherbivore, antimicrobial, allergenic contact dermatitis and antitumor activity of the isolated compounds are studied. The patterns of compounds encountered are used as genetic markers to understand phylogenetic relationships. New sequiterpene lactones, diterpene acids and flavonoid aglycones and their O- and C-glycosides have been isolated and structurally characterized by UV, NMR and MS spectral data as well as chemical derivatization and transformation.